Wet/dry vacuum cleaner filter for wet material collection

ABSTRACT

Vacuum cleaner filters, in particular replaceable vacuum cleaner filters suitable for both wet and wet/dry type vacuum cleaners are disclosed, as well as vacuum cleaner systems incorporating the use of such filters, and methods for their use. The filters include a filter element arranged in a closed circumferential, cylindrically-shaped path, a top end cap having a central orifice capable of constricting a post on a vacuum filter cage, and optionally a molded end ring oppositely-spaced from the top end cap for engagement with the lower motor housing of a vacuum cleaner.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 12/243,921, filed Oct. 1, 2008, now U.S. Pat. No.8,206,482, pending U.S. patent application Ser. No. 13/488,746, filedJun. 5, 2012, and pending U.S. patent application Ser. No. 14/021,959,filed Sep. 9, 2013, all claiming priority to U.S. Provisional PatentApplication Ser. No. 61/078,362, filed Jul. 4, 2008, the contents of allof which are incorporated herein by reference in their entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The inventions disclosed and taught herein relate generally to filtersfor vacuum cleaners, and more particularly relate to replaceable filtersfor wet/dry vacuum cleaners, as well as vacuum appliance systemsincorporating and using such filters.

2. Description of the Related Art

Vacuum appliances, in particular vacuum cleaners and wet/dry vacuumcleaners, whether they be strictly relegated to cleaning up drymaterials, or if they are capable of both wet and dry clean up, requiresome method to separate the dust and the dirt from the air that isexhausted back into the surroundings during operation. Typically, vacuumfilters are used in order to prevent debris from re-entering the areabeing cleaned. Hence, filters are commonly used to perform theseseparation functions. Associated with the use of such filters is often aneed to remove and re-attach the filter from the vacuum appliance, forexample, when cleaning the filter or replacing an old or damaged filterwith a new filter. Further, with regard to vacuum cleaners of the typeknown as “wet/dry” vacuum cleaners, the filter is often also removedwhen the vacuum cleaner is suctioning liquids. Consequently, specialstructures often accompany a typical wet/dry vacuum cleaner in order toaccommodate removing and replacing the filter.

With regard to the operation of a vacuum appliance or related air-movingsystem, it is typical that a suction system with a motor creates thevacuum and is mounted in a lid that is removably attached to acollection drum for receiving the vacuumed materials. A portion of thelid, herein termed a mounting assembly, extends at least partiallydownward into the drum and mounts a filter support assembly, commonlyreferred to as a “filter cage,” that generally covers a vacuum intake tothe suction assembly in the lid. The cage can be made of plastic such aspolypropylene, may be generally a cylindrically-shaped molded orextruded part having a series of axial and circumferential support ribswith a large percentage of open surface area to support the filterextended around the cage, and acts (at least in part) to prevent theunwanted radially inward collapse of the filter during vacuum operation.The axial ribs typically align with a longitudinal axis through the cageand the circumferential ribs are often at substantially right angles tothe axial ribs. This type of cage construction creates a relativelystiff component in the axial direction. In addition to supporting thefilter, the cage can provide a safety shield from user access to theimpeller, and may further optionally contain a float or similar devicethat protects the vacuum cleaner from water being inadvertentlysuctioned into the impeller.

The vacuum system inside the lid of the vacuum typically suctionsexternal dirty air or water through a hose into an opening in the drumor lid so that the dirt or water is deposited into the drum. Remainingmaterial, mainly air, then flows radially inward through the filter forremoval of dirt and debris and continues through the cage into a suctionimpeller in the lid, and then is exhausted from the vacuum cleaner.

The filter is commonly attached to the mounting assembly by a threadedstud, or “cage stem”, and nut combination on the end of the cage, whichacts to place the filter in axial compression, utilizing thelongitudinal stiffness of the axial ribs. In typical use, the filter isinserted over the cage, and a mounting flange of rigid material, such asplastic, is attached to the cage or mounting assembly and used tocompress or “sandwich” the filter between the flange and the mountingassembly. The compressive, mechanical force on the entire filter bodyand its filter element is the primary force used to seal the filter tothe vacuum cleaner and prevent unwanted leakage through the vacuumcleaner. Thus, a structurally sound and supportive cage is important tothe overall function of the filter and in general the vacuum cleaner.The filter may also be attached in position by some other method, suchas clamping one or more seals of the filter directly to the mountingassembly or lid. A structurally rigid cage is again necessary to guardagainst entry of unwanted objects, or fingers, into the impeller and tohouse the intake cutoff float.

Experience has shown that while these vacuum filter systems andmechanisms work, they often suffer from being awkward or cumbersome touse, which in turn makes the changing of the filter itself difficult,cumbersome, or time consuming. Further, those vacuum systems wherein thefilter is attached to a mounting assembly by way of a threadedstud-and-nut system on the end of the filter cage, using a threaded nutto retain the filter in a state of axial compression, can be timeconsuming to operate, and the employment of a separate filter nut orsimilar attachment mechanism is undesirable because such parts can bereadily lost or misplaced during the course of filter replacements.Additionally, some of the more complex filter system designs employmechanisms that add unnecessary cost to the overall vacuum applianceproduct. Finally, those filter system designs that do not use or requirefilter retaining mechanisms can often result in the filter becomingreadily dislodged and/or the seal of the filter to the vacuum is brokenwhen the vacuum is dropped or jarred, which in turn can damage both thefilter itself, and cause unwanted leakage of liquid or debris into thevacuum system and motor.

This application for patent discloses filter assemblies for use withvacuum appliances, such as wet/dry vacuum cleaners, which eliminates theneed for any separate retaining mechanism to install the filter to thevacuum appliance, allows the filter to be replaced and/or cleanedquickly and effectively, readily seals to the mounting assembly of thevacuum appliance, remains secure during normal operation withoutunwanted dislodgment from the jarring and rough handling of the vacuumappliance, and which is readily retro-fit to existing vacuum applianceunits already in the marketplace, negating the consumer from having topurchase a new vacuum appliance, such as a new wet/dry vacuum, in orderto use the filter assemblies of the present disclosure.

BRIEF SUMMARY OF THE INVENTION

The objects described above and other advantages and features of theinvention are incorporated in the application as set forth herein, andthe associated appendices and drawings, related to systems for both wetand dry debris pickup using a vacuum cleaner, such as a wet/dry vacuumcleaner.

The inventions described herein are to filter assemblies for use withvacuum appliances, systems including such filter assemblies, and methodsfor attaching such filter and filter assemblies to a vacuum appliance.In accordance with one aspect of the present disclosure, a filter foruse with a wet/dry vacuum appliance is described, wherein the filtercomprises a cap portion having a hole or formed opening extendingtherethrough; a spaced apart annular end ring; and a shaped filterspaced intermediate between the cap and the end ring and extending in aclosed, circumferential path that forms a closed, interior path, whereinthe hole or opening may be circumscribed by a retaining ring, andwherein the cap and the end ring are comprised of an flexible material.The cap may be substantially planar or substantially non-planar, and mayalso include one or more handles for use in improve the ease of removalof the filter assembly from a mounting post or stem of a vacuum filtercage. The annular hole or formed opening may be substantially centrallylocated in the cap portion of the filter assembly, or may be off-setfrom the axial center axis of the cap portion of the filter assembly, asappropriate. Additionally, the filter itself may becylindrically-shaped, oval-shaped, conically shaped, elliptical, orrectangular-shaped, without limitation, and may be pleated ornon-pleated, as appropriate.

In accordance with yet another aspect of the present disclosure, afilter for use with a wet/dry vacuum appliance is described, wherein thefilter comprises a cap having an annular hole or opening extendingtherethrough which may be centrally-located or not; an annular end ring;and a filter positioned intermediate between the cap and the end ringand extending in a circumferential path that forms a closed, interiorpath, wherein the annular hole is circumscribed by a retainingstructure, and wherein the cap and the end ring are comprised of aflexible material bonded to the filter, such that when the cap is inassociation with the wet/dry vacuum appliance, the cap seals on a planebelow the top surface of the filter. In a similarly related aspect ofthe instant disclosure, a filter for use with a wet/dry vacuum applianceis described, wherein the filter comprises a cap having acentrally-located annular hole extending therethrough; an annular endring; and a filter positioned between the cap and the end ring andextending in a closed, circumferential path that forms a closed,interior path, wherein the centrally-located annular hole iscircumscribed by a retaining ring, and wherein the cap and the end ringare comprised of a flexible material bonded to the filter. In furtheraccordance with this aspect of the present disclosure, a filter for usewith a wet/dry vacuum appliance is described, wherein the filtercomprises a cap having a centrally-located opening extendingtherethrough; an annular end ring; and a filter positioned between thecap and the end ring and extending in a circumferential path that formsa closed, interior region, wherein the cap and the end ring arecomprised of a flexible material, such as an elastomeric material,bonded to the filter. In further accordance with these aspects of thedisclosure, the centrally-located opening may be circumscribed by aretaining ring or similar retaining means, wherein the retaining ring iseither integrally formed with the cap, or is not integrally formed withthe cap.

In accordance with another aspect of the present disclosure, a filterassembly for use with a wet/dry vacuum appliance is described, whereinthe filter assembly comprises a cap having a centrally-located openingextending therethrough, and annular end ring, and a filter positionedbetween the cap and the end ring and extending in a circumferential paththat forms a closed, interior region, wherein the cap comprises a stemcover defining an inner region circumscribing the centrally-locatedopening, and wherein the cap and the end ring are comprised of aflexible material bonded to the filter.

In accordance with a further aspect of the present disclosure, a vacuumcleaner system for use in picking up both dry and wet debris using airmovement is described, wherein the system comprises a filter cageassociated with a lid assembly or motor housing of a vacuum cleaner, anda filter assembly. The filter cage assembly comprises a bottom face anda mounting post extending substantially perpendicular to the bottom faceof the filter cage. The filter assembly comprises a cap having acentrally located annular hole extending there through, an annular endring, and a filter spaced intermediate between the cap and the end ringand extending in a closed, circumferential path that forms a closedinterior path and wherein the centrally located annular hole iscircumscribed by a retaining ring which may be integrally formed withthe top face or non-integrally attached to the top face. In accordancewith this aspect of the disclosure, the annular hole has an area lessthan the area of the shaped, leading end of the mounting post, such thatthe annular hole of the filter assembly expands to fit over the shapedleading end of the mounting post as the post is pushed or pulled throughand then contracts once the leading end has passed through, allowing thefilter assembly to be retained in position against the bottom face ofthe filter cage by the integrally-formed retaining ring and theconstriction of the filter hole against the post. Additionally, themounting post of the filter cage may have any number of shapes,including an hour-glass shape, such that the hourglass shape may bedefined by two outer regions and an inner region, the outer regionshaving a diameter greater than the diameter of the inner region, andwherein such a shaped mounting post acts to enhance the seal of filterassemblies against the filter cage. In further accordance with thisaspect of the present disclosure, as a system, the filter assembly fitsover the top of the filter cage and the mounting post extends at leastpartially through the centrally-located opening in the cap of thefilter, and is retained in position by an integrally-formed retainingring on the cap, wherein the centrally-located opening has anuncompressed diameter smaller than a diameter of a portion of themounting post such that, during assembly, the centrally-located openingexpands in diameter to fit over a portion of the mounting post, andthereafter contracts in diameter so as to retain the filter over thefilter cage.

In accordance with another aspect of the present disclosure, a vacuumcleaner system is described, wherein the system comprises a filter cagecomprising a top face, a bottom face opposite the top face, and amounting post extending substantially perpendicular to the bottom faceof the filter cage; and a filter assembly comprising a cap having anopening extending therethrough, an annular end ring, and a filterpositioned between the cap and the end ring and extending in a closed,circumferential path that forms a closed interior path, wherein theopening in the cap is circumscribed by an elastomeric material, whereinthe filter assembly fits over the top of the filter cage and a portionof the mounting post extends through the opening in the cap of thefilter assembly and is retained in position by the elastomeric material,and wherein the opening in the cap has an uncompressed diameter smallerthan the diameter of a portion of the mounting post, such that duringassembly the opening expands in diameter to fit over the portion of themounting post, and thereafter contracts in diameter to retain the filterassembly over the filter cage.

In accordance with a further aspect of the present disclosure, a wet/dryvacuum cleaner is described, which comprises a filter cage including aprojection extending therefrom, the filter cage having a length; and afilter assembly which includes a cap formed of deformable material thatdefines an opening, and, a filter extending from the cap, wherein thefilter has a length that is longer than the length of the filter cage;wherein the filter is coupled to the cage by positioning the filterabout the cage such that the length of the filter extends along thelength of the cage and such that the projection from the filter cageextends through the opening of the filter cap such that the filter isretained in place at least in part by compressive forces resulting fromthe compression of the deformable material that defines the openingbeing applied against the projection; and wherein the engagement of theprojection with the opening causes a deformation of the deformablematerial such that the cap assumes a substantially conical shape. Infurther accordance with this aspect of the disclosure, the filter cagemay be attached to a motor housing of a vacuum appliance, wherein theconical shape formed by the deformed material is such that the point ofthe cone points in a direction towards the motor housing. In stillfurther accordance with this aspect of the disclosure, when the filtercage is attached to a motor housing of a vacuum appliance, the conicalshape formed by the deformed material is such that the point of the conepoints in a direction extending away from the motor housing.

In a further aspect of the present disclosure, an apparatus, such as avacuum apparatus or the like, is described, wherein the apparatuscomprises a filter cage that includes a first end and a second end and amounting projection extending from the second end; and, a filterassembly including a filter extending about the filter cage, the filterincluding a first end and a second end, a mounting cap positioned at thesecond end of the filter, the mounting cap being at least partiallyformed of flexible material and defining an opening; wherein themounting projection extends through the opening defined by the mountingcap such that the mounting cap engages a region of the mountingprojection; and wherein the distance from the first end of the filtercage to the region where the mounting cap engages the mountingprojection is less than the distance from the first end of the filtercage to the second end of the filter assembly.

In another aspect of the present disclosure, a method of attaching afilter to the filter cage of a wet/dry vacuum is described, wherein themethod comprises the steps of providing a filter cage that includes afirst end and a second end and a mounting projecting extending from thesecond end, the mounting projection defining a mounting region;providing a filter assembly including a first end, a second end, and amounting cap positioned at the second end of the filter, the mountingcap being at least partially formed of a deformable material anddefining an opening; positioning the filter assembly about the filtercage such that the filter assembly fits over the filter cage and suchthat the second end of the filter assembly is positioned closer to thesecond end of the filter cage than to the first end of the filter cage;and deforming the mounting cap to cause the mounting projection toextend through the opening in the end cap and to cause the end cap toengage the mounting region of the mounting projection.

In accordance with a further aspect of the present disclosure, a filterassembly for use with a wet/dry vacuum appliance is described, whereinthe filter assembly comprises a generally cylindrical filter comprisingpleated material, the filter defining a first end; and a mounting capcoupled to the first end of the filter, the mounting cap defining agenerally cylindrical opening near the center of the mounting cap and aring extending about the opening, wherein the mounting cap has anelastomeric characteristic that allows the mounting cap to be deformedto take a substantially conical shape, and wherein the ring has anelastomeric characteristic that allows the ring to be deformed such thatit exerts compressive forces radially inward towards the center of thecylindrical opening.

In a further aspect of the present disclosure, a filter assembly for usein a wet/dry vacuum that includes a mounting element is described,wherein the wet/dry filter assembly comprises a filter means forfiltering particulate matter collected by the wet/dry vacuum, andelastomeric retention means for creating compressive forces tending toretain the filter assembly in a fixed position with respect to a pointon the wet/dry vacuum when at least a portion of the mounting element ispositioned within an opening formed in the elastomeric retention means.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The following figures form part of the present specification and areincluded to further demonstrate certain aspects of the presentinvention. The invention may be better understood by reference to one ormore of these figures in combination with the detailed description ofspecific embodiments presented herein.

FIG. 1 illustrates a perspective view of an exemplary vacuum appliancesystem associated with the vacuum filters of the present disclosure.

FIG. 2 illustrates a perspective view of an exemplary vacuum filter ofthe present disclosure.

FIG. 3 illustrates a side elevational view of the vacuum filter of FIG.2.

FIG. 4 illustrates a bottom view of the exemplary vacuum filter of FIG.2.

FIG. 5 illustrates a perspective cross-sectional view of the filter ofFIG. 2, taken along line 5-5.

FIG. 6 illustrates a perspective view of an exemplary filter accordingto one embodiment of the present disclosure, shown in explodedorientation above a suction unit of a conventional wet/dry vacuum.

FIG. 7A illustrates a cross-sectional schematic view of an exemplaryvacuum cleaner mounting assembly with a filter of the present disclosuremounted thereto.

FIG. 7B illustrates a cross-sectional schematic view of an alternativevacuum cleaner mounting assembly with a filter of the present disclosuremounted thereto.

FIG. 7C illustrates a cross-sectional schematic view of a furtheralternative vacuum cleaner mounting assembly with a filter of thepresent disclosure mounted thereto.

FIG. 8 illustrates a perspective view of an alternative vacuum filterassembly of the present disclosure.

FIG. 9 illustrates a perspective view of a further alternative vacuumfilter assembly of the present disclosure.

FIG. 10A illustrates a side, cross-sectional view of the filter of FIG.9, taken along line 9-9.

FIG. 10B illustrates a top view of the filter of FIG. 9.

FIG. 11 illustrates a perspective view of a further alternative filterassembly of the present disclosure.

FIG. 12A illustrates a side, partial cut-away view of a filter cageassembly for use with the present disclosure, showing a retro-fit ofprior cages assemblies.

FIG. 12B illustrates a side, partial cut-away view of an alternativefilter cage assembly for use with the present disclosure, showing aretro-fit of a cage assembly.

FIG. 12C illustrates a partial, perspective view of the bottom face andmounting post of a further alternative filter cage assembly for use inaccordance with the present disclosure.

FIG. 12D illustrates a partial, perspective view of the bottom face andmounting post of an alternative filter cage assembly for use inaccordance with the present disclosure.

FIG. 12E illustrates a cross-sectional view of the filter cage assemblyof FIG. 12D, taken along line 12-12.

FIGS. 13A-E illustrate various alternative embodiments of the presentdisclosure.

FIG. 14A illustrates a further filter assembly in accordance with thepresent disclosure.

FIG. 14B illustrates a cross-sectional view of the filter assembly ofFIG. 14A, taken along line 14-14.

FIG. 15 illustrates a perspective view of an exemplary filter assemblyin accordance with the present disclosure.

FIG. 16 illustrates a perspective view of an exemplary filter assemblyin accordance with the present disclosure.

FIG. 17 illustrates a perspective view of a further exemplary filterassembly in accordance with aspects of the present disclosure.

FIG. 18 illustrates a side view of the filter assembly of FIG. 17.

FIG. 19 illustrates a perspective bottom view of the filter assembly ofFIG. 17.

FIG. 20 illustrates an exemplary top view of the filter assembly of FIG.17.

FIG. 21 illustrates a cross-sectional view of the filter assembly ofFIG. 20, taken along line 21-21.

FIG. 22 illustrates a view of the filter elements of the filter assemblyof FIG. 17.

FIG. 23 schematically illustrates a perspective view of a section of thefilter assembly of FIG. 17 in accordance with a further embodiment ofthe invention, wherein sections of layers are cut away to revealstructure that would not otherwise be visible to the viewer.

FIG. 24 illustrates a perspective view that schematically represents theembodiment of FIG. 23, with a filter element sandwiched between twodifferent filter elements.

FIG. 25 illustrates a top view of an embodiment of the presentinvention, wherein the top end plate of the filter assembly iscoincendent with the outer edge of the filter element.

FIG. 26 illustrates a bottom view of the filter assembly shown in FIG.25.

While the inventions disclosed herein are susceptible to variousmodifications and alternative forms, only a few specific embodimentshave been shown by way of example in the drawings and are described indetail below. The figures and detailed descriptions of these specificembodiments are not intended to limit the breadth or scope of theinventive concepts or the appended claims in any manner. Rather, thefigures and detailed written descriptions are provided to illustrate theinventive concepts to a person of ordinary skill in the art and toenable such person to make and use the inventive concepts.

DETAILED DESCRIPTION

The Figures described above and the written description of specificstructures and functions below are not presented to limit the scope ofwhat Applicants have invented or the scope of the appended claims.Rather, the Figures and written description are provided to teach anyperson skilled in the art to make and use the inventions for whichpatent protection is sought. Those skilled in the art will appreciatethat not all features of a commercial embodiment of the inventions aredescribed or shown for the sake of clarity and understanding. Persons ofskill in this art will also appreciate that the development of an actualcommercial embodiment incorporating aspects of the present inventionswill require numerous implementation-specific decisions to achieve thedeveloper's ultimate goal for the commercial embodiment. Suchimplementation-specific decisions may include, and likely are notlimited to, compliance with system-related, business-related,government-related and other constraints, which may vary by specificimplementation, location and from time to time. While a developer'sefforts might be complex and time-consuming in an absolute sense, suchefforts would be, nevertheless, a routine undertaking for those of skillin this art having benefit of this disclosure. It must be understoodthat the inventions disclosed and taught herein are susceptible tonumerous and various modifications and alternative forms. Lastly, theuse of a singular term, such as, but not limited to, “a,” is notintended as limiting of the number of items. Also, the use of relationalterms, such as, but not limited to, “top,” “bottom,” “left,” “right,”“upper,” “lower,” “down,” “up,” “side,” and the like are used in thewritten description for clarity in specific reference to the Figures andare not intended to limit the scope of the invention or the appendedclaims.

In general terms, Applicants have created filter assemblies for use withvacuum appliances, such as wet/dry vacuum cleaners, which eliminate theneed for separate retaining mechanism to install the filter to thevacuum appliance, allows the filter to be replaced or cleaned quicklyand effectively, seals automatically to the mounting assembly of thevacuum appliance, remains secure during normal operation withoutunwanted dislodgment from the jarring and rough handling of the vacuumappliance, and which is readily retro-fit to existing vacuum cleanerunits already in the marketplace.

Turning now to the figures, FIG. 1 illustrates a schematic, perspectiveview of an exemplary vacuum appliance system 10 for use with the filtersystems of the present disclosure, wherein the system shown is a wet/dryvacuum appliance 20 comprising a collection drum or chamber 30, casters42 mountable on the bottom end 32 of the drum 30, and a lid 50 removablyattached to top end 34 of the collection drum 30 containing a powerhead.The lid 50 is removably attached (e.g., via a hinge mechanism or thelike, or via completely lifting off from the top of drum 30 by releasinglatches 54) to the collection drum 30 so that the lid can be readilyremoved so as to empty debris or liquids contained within the drum, oras relates to the present disclosure, to change or clean the filterassembly (not shown) that is typically mounted in association with theunderside of a motor housing, powerhead, or lid of the vacuum appliance.As with most known wet/dry vacuum cleaners, a motor (not shown) isgenerally coupled to the mounting assembly on the inside portion of lid50 of the vacuum cleaner 20, which is operable to create the vacuuminside the collection drum 30 so as to draw solid debris, liquid, orboth into the collection drum 30 through an inlet port 60 by way of avacuum hose (not shown). The collection drum 30 may also optionallyinclude a drain 40 so that liquid within the drum can be emptied (e.g.,via a pump such as that described in U.S. Design Pat. No. D551,681) andremoved without having to undo and remove the lid 50. Vacuum appliancessuch as the system 10 generally include a filter assembly as will bedescribed herein, as well as a mounting assembly and/or a filter cage(not shown) which will be described in more detail herein, and which istypically coupled to or integrally formed with the underside of the lid50 or motor housing, extending downwardly into collection drum 30.

The vacuum appliance itself, including the collection chamber/drum 30and the lid and powerhead 50 may be made of any number of lightweight,relatively inexpensive plastics or polymers of suitable strength andrigidity, including but not limited to polypropylene, polyurethane, andother similar materials. The motor frame and other select parts of thegeneral vacuum assembly may be made of a material more rigid and havinga smaller flex modulus than that comprising the collection chamber,exemplary materials including but not being limited to glass-filledpolyester, glass-filled polycarbonate, thermoset polyester, and similarpolymeric materials, all of which are heavier, and often more expensive,than the material used to make the collection chamber.

FIGS. 2-5 illustrate a filter assembly 100 in accordance with aspects ofthe present disclosure. In FIG. 2, a perspective view of filter assembly100 is illustrated, which comprises an integrally-formed an integratedend plate section 110, an end sealing ring 130 (not shown), and, agenerally cylindrically-shaped, pleated filter element 120 intermediatebetween plate 110 and end sealing ring 130 and extending in a closed,circumferential path which includes and forms a closed, interior region.The integrated end plate 110, equivalently referred to herein as a“cap”, may further, optionally comprise one, two or moreintegrally-formed handle portions 112, 114 (two are shown), and a formedhole or opening 118 in the center of the end plate, centrally-formedhole 118 extending from the top surface 111 of end plate 110 through tothe closed, interior airflow path formed by filter element 120. The endplate, or cap, 110 may also optionally comprise a plurality (two ormore) of integrally-formed support struts 115, to add structuralintegrity to the end plate itself. As shown in the figure, the handleportions 112 and 114 may be substantially diametrically opposed inorientation, and can extend partially over the top and edges of thepleated filter element 120, so as to allow for providing the user with agripping surface to aid in filter removal from the filter cage of avacuum appliance when changing filters. While two handle-portions 112and 114 are illustrated, it will be recognized that the filterassemblies described herein may have no handles, a single handle, ormore than two handles, which may be oriented in a variety of manners,such as perpendicular to the top face of the cap portion, withoutlimitation As also illustrated in FIG. 2, the hole 118 in end plate 110can be circumscribed by an integrally- or non-integrally formed annularretaining means, such as retaining ring 116 having a general taurus-like(donut) shape of such a size, shape and internal diameter that the ballor end flange on the leading end of mounting shaft on a vacuum's filtercage can be forced up and through the hole 118 as will be discussed inmore detail below, so as to retain a filter assembly of the presentdisclosure on the filter cage and seated against the base of the vacuumappliance. If retaining ring 116 is integral, it will be formed into endplate 110 as part of the manufacturing process. In the event that ring116 is non-integral and is a separate element of the filter assembly, itmay be attached to the top surface 111 through any number of appropriatechemical (e.g., glue) or mechanical methods, without limitation.

FIG. 3 illustrates a side view of filter assembly 100, showing inparticular the dimensional relationships between the integrated cap, orend plate, 110, the filter element 120, and the end seal ring 130. Asshown therein, in one non-limiting, exemplary aspect of the disclosure,the integrated top mounting cap 110 has an outer diameter d₁ which isequal in all orientations, due the substantially circular shape of cap110. Filter element 120, which is integrally attached to cap 110, has anouter diameter d₃. In accordance with this non-limiting, exemplaryaspect of the present disclosure, the outer diameter d₃ of filterelement 120 can be greater than the outer diameter d₁ of cap 110. In thealternative, the end plate 110 may have a diameter d₁ which issubstantially the same as, or is coincident with, the outer diameter d₃of filter element 120. As illustrated, only the formed handles 112, 114extend outwardly in such a manner as to extend over the outer edge offilter element 120, such that the diameter d₂ between the outer edges ofthe handles is greater than the outer diameter d₃ of filter element 120.However, viewing FIG. 2 in combination with FIG. 3, it will be notedthat in accordance with certain aspects of the disclosure, the majorportion of cap 110 circumscribes the top end of filter element 120, suchthat more than 50% of the outer diameter d₁ of cap 110 is less thanouter diameter d₃ of filter element 120. In accordance with exemplary,non-limiting aspects of the present disclosure, the diameter d₁ ofgreater than 50% of the cap 110 to the outer diameter d₃ of filterelement 120 has a ratio ranging from about 1.0:1.1 to about 1.0:2.0,inclusive, preferably ranging from about 1.0:1.1 to about 1.0:1.5, orfurther preferably ranging from about 1.0:1.2 to about 1.0:1.4.Additionally, and by way of non-limiting example only, the ratio betweenouter diameter d₁ and the height h₁ of filter element 120 may be inratio ranging from about 1.0:1.3 to about 1.0:1.8, preferably from about1.0:1.4 to about 1.0:1.6. Finally, as illustrated in FIG. 3, theintegrally-formed end seal ring 130 has an outer diameter d₄ that isless than the outer diameter d₃ of filter element 120, and issubstantially equal to the outer diameter d₁ of cap 110. However, thisdiameter/size relationship between the end seal ring 130 and the filterelement 120 may not be limited to this illustrated situation, such thatsituations wherein the outer diameter d₄ of end seal ring 130 may besubstantially the same as, or coincident with, the outer diameter d₃ offilter element 120. In an exemplary, non-limiting aspect, a filterassembly 100 may have a filter height h₁ of about 8.25 inches, a filterouter diameter d₃ of about 6.5 inches, and end plate 110 and end sealingring 130 diameters of about 5.38 inches, with the diameter d₂ spanninghandle portions 112, 114 being about 7.5 inches. As indicated above,however, these dimensional relationships are not limiting, and it isequally acceptable for the end plate 110 and/or end sealing ring 130 tohave an outer diameter greater than that of the outer diameter of thefilter 120, or alternatively substantially equal to (substantiallycoincident with) the outer diameter of the filter element 120.Additionally, in accordance with certain aspects of the presentdisclosure, annular end sealing ring 130 need not be included in thefilter assembly in order to provide support at the bottom end of thefilter, or to aid in providing a sealing surface against the motorhousing of a vacuum appliance. In such instances, support for the filterassembly may be accomplished through the inclusion of an internalsupport web or mesh, such as a metal mesh support assembly (not shown),which circumscribes the interior region of the filter element 120.

In FIG. 4, a bottom view of the vacuum filter assembly of FIG. 2 of thepresent disclosure is shown. As seen in the figure, hole 118 extendsthrough annular retaining ring 116 on the top surface 111 of end plate110 to bottom face 113 of end plate 110. FIG. 4 also illustrates theclosed, interior path of filter 100 formed by the circumferential pathof filter element 120. This interior path is the portion of the filterassembly which, in typical use, is fit over the filter cage of a vacuumappliance, whereupon the leading end of the mounting shaft extends upand through central hole 118, as will be described in more detail withreference to FIG. 6 and FIG. 7.

FIG. 5 illustrates a perspective cross-sectional view of an exemplaryfilter 100 of the present disclosure as illustrated in FIG. 2, takenalong line 5-5, and showing the filter seals, filter element, and cap110. As is more clearly seen in this view, the outer edges of the filterelement 120 extend past the outer edge, or diameter, of both theintegrated end cap 110 and the annular end ring 130, save for portionsof handles 112 and 114 integrally formed with end cap 110, which have alip 117 to enhance the grip for the user and which extends a distancedown and over the outer edge of the filter element 120. The plurality ofintegrally-formed support struts 115 on the top surface 111 of cap 110act to add strength to the end cap 110 and provide additional mechanicalsupport to the filter assembly during typical operation and assembly incombination with a filter cage of a vacuum appliance, which will bedescribed in more detail below. While the support struts 115 are shownto arranged in a radial manner, extending outward from the annular ring116, they may also be arranged in a concentric manner on the top surface111 of end plate 110.

The end cap 110, as well as the integrated end ring 130, may be madefrom any conventional rigid or semi-rigid material having a flexibilitygreat enough to go over the “ball” or equivalent shaped structure 82 onthe leading end of the stem 80 of the filter cage 90 and form a seal, asillustrated in FIG. 6, including but not limited to plastics andpolymers such as polyvinyl chloride (PVC), metals such as steel, andelastomeric materials that are suitable for absorbing energy and forminga retaining seal, particularly under vacuum conditions, such materialsincluding but not limited to polyurethane elastomers and the like. Theterm “elastomer”, or “elastomeric”, as used herein, refers generally tocompositions or materials that have a glass transition temperature,T_(g), at which there is an increase in the thermal expansioncoefficient, and includes both amorphous polymer elastomers andthermoplastics. Specifically preferred for use herein are elastomerswhich have low T_(g)'s, e.g., below 600° F. (315.5° C.), densities (orspecific gravities) less than about 50 lb/ft³, and tensile strengthsranging from about 10 PSI (about 68,947.572 Pa) to greater than about100 PSI (about 689,475.728 Pa). This includes but is not limited topolyolefin elastomers, polyurea elastomers, polyurethane elastomers,latexes, and thermoplastic compounds/elastomers. As used herein, theterm “elastomer” or “elastomeric compound” may also include silicone- orsilica-based elastomers, or silicone-containing elastomers or rubbers.Exemplary elastomers and rubbers compounds which may be used in formingthe filter assemblies described herein include but are not limited toacrylonitrile-butadiene rubbers (NBR) such as Buna-N, hydrogenatednitrile rubbers, ethylene-propylene elastomers, fluorocarbon rubberssuch as VITON™, chloroprenes, silicone rubbers and elastomers,fluorosilicone rubbers and elastomers, polyacrylate elastomers, ethyleneacrylic elastomers, styrene-butadiene rubbers (SBR), polyurethanesincluding both polyester and polyether urethanes, and natural rubbers(NR).

In particular, in accordance with one aspect of the present disclosure,the end cap 110 and the end ring 130 are comprised of an elastomericmaterial, preferably a polyurethane foam, and more particularly it istwo-part polyurethane foam, such as those two-part polyurethane foamsthat comprise a mixture of an isocyanate and a resin. In accordance withcertain aspects of the present disclosure, the two-part polyurethanefoam may be made of the Elastoflex™ material manufactured by BASFCorporation of Livonia, Mich. Exemplary, non-limiting two-partpolyurethane foams have a mix ratio of between about 1:1 and about 3:1,resin to isocyanate, this ratio being inclusive. Suitable, alternativeelastomers which may be used to form one or both of the cap 110 and theend ring 130 include but are not limited to polyurethane (commercialexample including Lupranat™, Lupranol™, Lupraphen™, Elastoflex™, andCellasto™, expandable polystyrene (EPS; commercial examples includingStyropor™ and Neopor™, both expandable polystyrene (EPS) materialsavailable from BASF), extruded polystyrene (XPS; commercial examplesincluding Styrodur™ C or Peripor™ from BASF), melamine resin (such asBasotect™), or polypropylene (such as Neopolen P™).

The elastomeric materials used to manufacture both the integrated endcap 110 and the integrated end ring 130 are preferably of the same type,and further have a variety of physical and mechanical properties thatallows the overall filter assemblies disclosed herein to perform in theadvantageous manner described. Exemplary characteristics of the materialinclude density, tear resistance, elongation, set compression, shore “A”hardness, tensile strength, hardness, static modulus, and resistance toa number of organic solvents due to the crosslinking structure of theelastomeric material, among other features. Exemplary, non-limitingphysical and mechanical property ranges are shown in Table 1, as well asexemplary (non-limiting) measurement standards which may be used toobtain data for the listed physical and/or mechanical properties of theelastomeric materials. In accordance with the present disclosure, theelastomeric materials used to form both the integrated end cap 110 andthe end ring 130 may have two or more physical characteristics orproperties as set forth in Table 1, such as tensile strength,elongation, and closed cell content.

TABLE 1 Physical and Mechanical Characteristics of elastomeric materialssuitable for use in forming portions of filter assemblies of the presentdisclosure. Exemplary Range Physical/Mechanical Property MeasurementStandard Values¹ Density ASTM D1564, D1622 16-25 lb/ft² TensileStrength³ ASTM D1564, D412 150-220 psi Elongation ASTM D1564, D41290-200% Tear Resistance, Die “C” (PLI) ASTM D624-00(2007) 20-40Compression Set ASTM D1564/D3576 11-70% Shore “A” Hardness (free riseISO 7619 30-40 pts. molded) ASTM D1415, D2240 Closed Cell Content ASTMD-2856 80-99% Dielectric Strength2 ASTM D149-97a 20-100 kV/in. ¹Allvalue ranges temperature required by the listed test standard.2Dielectric strength is the measure of the ability of an elastomer toresist current flow when voltage is applied. ³As used herein, the term“tensile strength” refers to the maximum amount of tensile stress thatcan be applied to the elastomeric material before it ceases to beelastic, measured in units of force per unit area (N/m² or Pa) accordingto ASTM-standard D-638, ASTM D-412, or ISO 37 (available from the worldwide web at astm.org).

In accordance with further aspects of the disclosure, the end plate, orcap, 110 may also be made of non-elastomeric materials for use inspecific operational environments. For example, and without limitation,the end plate 110 may be made of metal, preferably a non-corrosive metalmaterial.

The filters, such as filter element 120, suitable for use in the filterassemblies of the present disclosure may be of the pleated type asillustrated, or may be non-pleated, and may be made of any number ofsuitable filtration materials, including but not limited to paper;cloth; glass-fiber materials; split-fiber materials; solution-spunfibers and materials made from such fibers; felt materials; naturalfiber filter material; expanded polytetrafluoroethylene (PTFE)membranes; expanded ultra high molecular weight polyethylene (PE)membranes and materials; melt-blown media, such as melt-blownpolypropylene (PP) or melt-blown polyethyelene (PE); microporous opencell polymers, such as polyurethane foam; poly(ethylene terephthalate),(PET) or polyphenylene sulfide (PPS) based materials, as well ascopolymer-based materials thereof, HEPA-type materials and related fiberor randomly-arranged fiber materials (high-efficiency particulate air(HEPA) filters being those filters which can remove at least 99.97% ofairborne particles 0.3 micrometers μm) in diameter) in accordance withNIOSH requirements; triboelectrified media and materials, and the like,any of which may be treated so as to be hydrophobic and/or have mold andmildew preventative characteristics. Such treatments may be especiallydesirable for those filter assemblies manufactured for use in wet/dryvacuum cleaners. Filter element 120 may be folded or pleated, asillustrated in the figures, e.g., FIG. 2, or it may be non-folded, asappropriate. Preferably, in accordance with one aspect of the presentdisclosure, and regardless of which material is used to form filterelement 120, the filter material is folded into multiple pleats andformed into a generally cylindrical or tube-like shape having a“rippled” or “pleated” appearance, so as to increase the exposed surfacearea. This folding increases the area of the filter that is in contactwith the airstream during vacuum appliance operation, thus effectivelyimproving the filtration without decreasing the airflow. The filters mayalso have a variety of porosities, or pore size distributions, dependingupon the desired air flow permeability to be achieved. Exemplaryporosities include, but are not limited to, about 1 micron, about 3micron, and about 10 microns, as well as porosities greater than or lessthan these values, e.g., about 0.1 microns, and about 15 microns. Suchporosity values, as used herein, mean that the filter will stop at least99% of all particles that are of the target particle size (e.g., 10microns) or large. Porosity measurements can be by any appropriatemeasurement method or device, such as with a Coulter Porometer™ (CoulterElectronics, Inc., Hialeah, Fla.), or using industry standard testingmethods, such as ASTM F316-03 (available from the American NationalStandards Institute). Such porosities result in filters according to thepresent invention having air flow permeabilities ranging from about 2cfm/ft² to about 80 cfm/ft². In general, however, the filter elements120 are relatively stiff and simultaneously flexible in nature in orderto hold their shape, and will have a porosity as desired in order tofilter dry materials, such as dust, drywall dust, dirt, fireplace ashes,and the like out of an air stream during operation of the vacuum cleanerwhile allowing air to flow through it to an outlet through the vacuumlid.

As indicated, the filters of the present disclosure may also optionallyfurther comprise one or more biostatic and/or biocidal agents. Suitablebiostatic or biocidal agents are typically selected to havebacteriostatic and/or fungistatic properties which may be used to treatthe filters of the present disclosure and reduce biologic contamination(e.g., mycotoxin contamination) of the air passing through the vacuumappliance and using such a filter. Exemplary biostatic and/or biocidalagents which may be used for this purpose include but are not limited to2-bromo-2-nitropropane-1,3-diol, isothiazolines, methyl or propyl orbutyl parahydroxybenzoates, sorbic acid, benzoic acid and salts of theseacids, phenoxy ethanol, triclosan, diclosan, dichlorophen, chlorhexidinegluconate, orthophenylphenol, quaternary biocides,orthobenzylparachlorophenol, and substituted diphenyl ethers, as well ascombinations thereof. In order to enhance the application or use of suchbiological inhibitors, a number of additional additives may be appliedto the filter, or combined with the biocidal or biostatic agents appliedto the filter, including but not limited to humectants, rheologicaladditives, and surfactants. The humectant may be selected from calciumchloride, glycerol, sorbitol, ethylene glycol, polyethylene glycol(PEG), propylene glycol, 1,3 butylene glycol, sodium sulphate, sodiumchloride and sodium dioctylsulphosuccinate. The rheological additive istypically a thickening agent, a gelling agent or a viscosity modifier,and may be one or more compounds selected from sodiumcarboxymethylcellulose (CMC), hydroxyethylcellulose (HEC),hydroxypropylcellulose (HPC), polyethylene glycols, polypropyleneglycols, polyvinyl alcohol, polyvinyl acetate (PVA),polyvinylpyrrolidone and copolymers of these, hydroxypropyl guar,xanthan gum, chitosan, acrylated copolymers, polyacrylic polymers(carbopols) and water soluble polymers, as well as combinations thereof.Preferably, the composition remains effective, in service, for periodsof 6 months or more, such that the filter, after 3 months in normal use,produces at least log 1 reduction in cfu's/gram of clean filter materialin comparison with an untreated filter under the same conditions.

Additionally, while the filter assemblies described herein have beenillustrated and described generally with reference to a cylinder-shapedassembly, it is envisioned that these filter assemblies may be of anynumber of other suitable shapes, including but not limited to oval-typecylinder, conical, elliptical, square, rectangular, and hexagonal.

An exploded view of a filter assembly 100 in association with the filtercage assembly of a typical vacuum appliance is illustrated in FIG. 6,wherein the filter cage 90 forms a part of the suction unit 70 which isoften an integral part of vacuum lid 50 and mounts on the top of avacuum appliance collection drum 30 (see, FIG. 1) for collecting debrisin the form of dirt, dust, saw dust, water, and other liquids. Thegeneral suction unit 70 as illustrated typically includes an opening(not shown in this view) to which a vacuum hose is attached (e.g., 60 inFIG. 1), an exhaust 74, a float ball or valve 76 as a safety precautionto turn off the suction unit 70 when a liquid fills the drum 30, andlatches 54 a, 54 b for releasably securing the suction unit 70 to thecollection drum 30. Filter cage assembly 90, as well as other filtercage assemblies described herein, comprises a first end comprising a topface (not shown), and a second end comprising a bottom face 78 oppositeand spaced apart from the top face, wherein the filter cage assembly istypically attached to a motor housing or suction surface 72 of thevacuum appliance, the bottom face being available for coupling with afilter or filter assembly such as described herein. The filter cageassembly 90 extends downwardly away from and generally perpendicular tosuction surface 72 of the suction unit 70, and may be mold-formed withunit 70, or may be a separately-formed assembly that is attached to andintegrated with the suction unit 70 using any number of appropriateattachment means. The filter cage assembly 90 also typically comprises aplurality of energy-absorbing structural ribs 77 which form a supportfor the cage, and which can act to at least partially absorb impact orother stress loads applied to the cage during normal use and operationof the vacuum appliance. Ribs 77 may be formed in a parallel arrangementas illustrated, or may be oriented in a variety of other orientationswhile maintaining the desired structural support, such as inlongitudinally angled to form a “barber-pole” type arrangement aroundthe perimeter of the cage. Assembly 90 may also comprises a mountingpost or threaded bolt 80 extending downwardly from and substantiallyperpendicular to the bottom face 78 of the filter cage assembly 90, thedistal end of which may optionally further comprise anintegrally-formed, shaped head 82 which can act to further retain thefilter assembly over the filter cage assembly 90. Mounting post 80 maybe substantially cylindrical in shape, or as illustrated in FIG. 6, mayhave an hour-glass shape, such that the base of the post slopes towardsthe bottom face 78 of the filter cage assembly 90, while the leading end82 is a shaped head having a diameter greater than the diameter of thepost itself. While the shaped head at leading end 82 is illustrated tobe spherical in shape, it is by no means limited to such a shape, andcan take any number of geometric shapes, so long as the diameter of thehead is greater than the diameter of the post 80 at its narrowest point.Additionally, the hour-glass shape of the post 80 advantageouslyimproves the seal of the filter assemblies described herein against thebottom face of the filter cage, in combination with the effect of theannular retaining ring 116. In accordance with the present disclosure,the filter assemblies described herein fit over the bottom face of thefilter cage 90, wherein a portion of the mounting post 80, such asleading end 82, extends through the opening in the cap of the filterassembly and is retained in position by the elastomeric material of thecap and/or a retaining ring or means associated with the filter assemblycap 110.

When the filter assemblies of the present disclosure are constructed inthe manners disclosed herein, the filter assemblies 100 (and 300, 400and 600) have an open end opposite the integrated end cap 110 which iscircumscribed by the integral end ring 130 (see FIGS. 3-5) that isadapted to tightly interface with the exhaust section of the suctionunit 70 of the vacuum assembly. The filter unit assembly 100 shown inFIG. 6 includes a centrally-located (e.g., circumscribing the verticalaxis of the filter assembly) annular hole/opening 118 in its integratedend cap 110, surrounded by an annular retaining ring 116 as describedpreviously. This annular hole is preferably smaller in diameter than theleading end 82 of post 80 on the filter cage. In a typical application,the post 80 (or bolt) located on the bottom face 78 of the filter cageassembly 90 as shown is passed through the opening 118 in the end cap110, whereupon the hole 118 in the filter assembly expands so as to goover the ball (or other formed portion) on the leading end 82 of thepost 80, and then contracts again to its original size after passingover leading end 82, so as to hold the filter assembly 100 in place onthe suction unit surface 72. Stated another way, the opening 118 in theend cap 110, in accordance with the present disclosure, has anuncompressed diameter smaller than the diameter of a portion of themounting post, such that during assembly, the opening 118 expands indiameter to fit over a portion of the mounting post 80, such as leadingend 82, and thereafter contracts in diameter so as to retain the filterassembly over the filter cage assembly 90. Due to the size andelastomeric characteristics of the annular retaining ring 116 detailedabove, the filter unit assembly 100 is tightly retained in place overthe filter cage assembly 90 without the need for additional retainingmeans or mechanisms, such as a nut or similar mechanical means. Uponsuch mounting of the filter unit assembly, the integral end ring 130acts as a gasket element to form a tight fit against a sealing surface72 on the suction unit 70 when the filter assemblies described hereinare retained in place as illustrated and described. Additionally, duringoperation of a vacuum assembly, the filter seal itself is improved bythe force of the vacuum which pulls the filter assembly into a tightseal against the shaped filter cage mounting post 80. In certain aspectsof the present disclosure, as will be described in more detail belowwith reference to FIGS. 7A-7C, when the filter assembly described hereinis coupled to the filter cage, the engagement of the projection, ormounting post, 80 with opening 118 can result in a deformation of thedeformable material such that the cap assumes a substantially conicalshape, wherein the point of the cone is such that it points eithertowards or away from the motor housing.

In accordance with the present disclosure, the general method ofattaching a filter assembly as described herein, such as filter assembly100 (or any of the other filter assemblies described herein), to afilter cage 90 of a wet/dry vacuum appliance comprises the steps ofproviding a filter cage that includes a first end and a second end and amounting projecting extending from the second end, the mountingprojection defining a mounting region; providing a filter assemblyincluding a first end, a second end, and a mounting cap positioned atthe second end of the filter, the mounting cap being at least partiallyformed of a deformable material and defining an opening; positioning thefilter assembly about the filter cage such that the filter assembly fitsover the filter cage and such that the second end of the filter assemblyis positioned closer to the second end of the filter cage than to thefirst end of the filter cage; and deforming the mounting cap to causethe mounting projection to extend through the opening in the end cap andto cause the end cap to engage the mounting region of the mountingprojection. This method is not intended to be limiting in any way, butis a general method appropriate for use with the filter assemblies andsystems described herein.

FIG. 7A illustrates a cross-sectional schematic view of a vacuum cleanermounting assembly with a filter assembly 100 of the present disclosuremounted thereto, such as that from the exploded view in FIG. 6. As showntherein, when filter assembly 100 is mounted over filter cage assembly90, at least a portion of post 80 extends above the top surface 111 ofcap 110 and annular retaining ring 116. In accordance with aspects ofthe present disclosure, in the instance where the post 80 has a formedhead 82 at its leading end, the formed head 82 preferably clears the topof ring 116 and further acts to retain the filter assembly 100 over thefilter cage 90 during normal operation of a vacuum appliance, such as awet/dry vacuum cleaner. FIG. 7A also illustrates one of severalacceptable manners in which end ring 130 mates with and forms a sealagainst sealing surface 72 of the vacuum appliances suction unit 70. Thedirectional arrows indicate the direction of vacuum force duringoperation of a vacuum appliance, illustrating again the improved filterseal formed by the use of the filter assemblies described herein,wherein the force of vacuum acts to pull the filter assembly tightlyagainst the shaped filter-cage mounting post 80. In accordance with theaspect illustrated in FIG. 7A, the engagement of mounting post 80 withopening 118 can result in very little deformation of the deformablematerial that forms and defines 118 or the cap of the filter assemblyitself, resulting in the cap of the filter assembly assuming a shapethat is substantially parallel to the bottom face 78 of the filter cage.

FIG. 7B illustrates a cross-sectional schematic view of an alternativevacuum cleaner mounting assembly with a filter of the present disclosuremounted thereto, wherein the surface of the cap 110′ is non-planar, andconical in its manner of contact with the top surface 78 of filter cage90. As shown therein, engagement of the mounting post/projection 80 withthe opening 118′ of the filter assembly causes a deformation of thedeformable material the forms the cap 110′ and defines the opening 118′,as well as the optional retaining member 116′, such that the capeassumes a substantially conical shape, the conical shape formed by thedeformable material being such that the point of the cone points in adirection towards the motor housing of the vacuum appliance (not shown).

FIG. 7C illustrates a cross-sectional schematic view of an alternativevacuum cleaner mounting assembly with a filter of the present disclosuremounted thereto, wherein the surface of the cap 110″ is in a non-planar,frusto-conical contact arrangement with the top surface 78 of filtercage 90. As shown in the figure, the frusto-conical arrangement of cap110″ with the top surface 78 of the filter cage allows for a non-planaroffset of some angle, a, between the filter assembly 100″ and the filtercage 90, while maintaining appropriate surface contact and seal suchthat vacuum may be maintained during normal operational use. As showntherein, engagement of the mounting post/projection 80 with the opening118″ of the filter assembly causes a deformation of the deformablematerial the forms the cap 110″ and defines the opening 118″, as well asthe optional retaining member 116″, such that the cap assumes asubstantially conical shape, the conical shape formed by the deformablematerial being such that the point of the cone points in a directionaway from the motor housing of the vacuum appliance (not shown).

FIGS. 8-10 illustrate alternative, yet equally acceptable embodiments ofthe present disclosure. In FIG. 8, a filter assembly 300 is illustratedin perspective view, the assembly comprising an integrated cap section310, an end ring 330 (not shown), and a cylindrically-shaped, pleatedfilter element 320 intermediate between cap 310 and end ring 330. Theintegrated cap 310 comprises two handle portions 312, 314 and a formedhole 316 in the center of the cap. As with the filter assembliesdescribed above, the handle portions 312 and 314 extend partially overthe top and edges of the pleated filter element 320, and act to allowfor providing the user with a gripping surface to aid in filter removalfrom the filter cage of a vacuum appliance when changing filters. Asillustrated in FIG. 8, the hole 316 in cap 310 is generally centrallylocated about the vertical or longitudinal axis of the filter assembly,and is formed in a generally annular, taurus-like shape of such a size,shape and internal diameter that the ball or end flange on a filter cagecan be forced up and through the hole 316 so as retain the filterassembly on the filter cage and seated against the base of the vacuumappliance. As in the embodiments described above, the elasticity andphysical characteristics of the material forming the cap 310, and inparticular the hole 316, allows the end cap 310 to become sealed aroundthe flange of a filter cage (not shown) after installation.

FIGS. 9 and 10A-10B illustrate a further embodiment of the filterassemblies of the present disclosure. A perspective view of such afilter assembly 400 is illustrated in FIG. 9, the assembly 400comprising a fully integrated cap 410, flanges 412 and 414, acylindrically-shaped, pleated filter element 420, and an integrated endring 430 spaced opposite and parallel to cap 410, such that the pleatedfilter 420 is intermediate therebetween. Cap 410 may be made from any ofthe polymeric materials described above, preferably from a polyurethanesuch as an ELASTOPLEX® (available from B.A.S.F. Corporation) polymer orfoam. Fully integrated cap 410 extends across the entire top diameter ofthe filter element 420, and integrally retains filter element 420 inpart via lip 405 which is a formed part of cap 410, and which bothcircumscribes the outer edge of cap 410 and extends a distance d₆ alongthe outer edge of filter 420, perpendicular to the top face of cap 410.Flanges 412 and 414, as shown herein, may be of any appropriate shapeand size, such that they may be gripped by the user in installing orremoving the filter 400, and preferably extend upwardly from the topface 402 of cap 410. Additionally, while flanges 412 and 414 may beformed separately and attached to the top face 402 using any appropriatemethods, such as through the use of adhesives, flanges 412 and 414 arepreferably integrally formed with the cap 410. FIG. 10A illustrates acut-away side view of the assembly 400 of FIG. 9, taken along line 9-9,as it appears either during removal from a vacuum filter cage 500, oralternatively, and as described above with reference to a separatefilter assembly 100, engagement of the mounting post/projection 502 withthe opening 418 of the filter assembly may cause a deformation of thedeformable material the forms the cap 410 and defines the opening 418,such that the cap assumes a substantially conical shape, the conicalshape formed by the deformable material being such that the point of thecone points in a direction towards the motor housing of the vacuumappliance. As is more clearly seen in this figure, the projection 502,integrally formed with the top face 501 of cage 500 associated with avacuum appliance (not shown) extends through opening 418 in integratedcap 410 in a manner as described above, wherein the opening 418 has anuncompromised diameter smaller than a diameter of a portion of theprojection 502, or the leading end 504 thereof, such that, duringassembly, the opening 418 expands in diameter to fit over a portion ofthe projection 502, and thereafter contracts in diameter so as to retainthe filter over the cage 500.

FIG. 10B illustrates a top-view of an alternative aspect of the filterof FIG. 9, wherein the assembly comprises an integrated, top cap 410′,two (or more) upwardly extending flanges 412 and 414 formed on the topface of cap 410′, a pleated filter element 420, and a hole 418 formed inthe center of cap 410′ and surrounded by an integrally-formed,taurus-shaped retaining ring 416. Similar to the filter assembliesdescribed above, the physical characteristics (e.g., elasticity) of thematerial forming the top cap 410′ and/or the retaining ring 416circumscribing the hole 418 allows the end cap 410′ to seal around theflange of a filter cage after installation over a filter cage in avacuum appliance. The aspect illustrated in FIG. 10B differs from thatshown in FIG. 9 in that the cap 410′ has a top diameter that is lessthan the diameter of the filter element 420, such that the ends offilter element 420 extend outwardly past the edge of cap 410′.

FIG. 11 illustrates a further aspect filter assembly embodiment 600 ofthe present disclosure, comprising a plurality of handles 612, 614. Asillustrated in the figure, the assembly 600 comprises a top cap portion610, a lower end ring 630, and a pleated filter element 620 spacedintermediate between the cap 610 and the lower end ring 630, wherein thecap 610 and the end ring 630 are bonded to the filter 620. Top capportion 610 comprises an annular hole 616 extending through its entirethickness, as well as an optional, taurus-shaped ring 618 circumscribingthe annular hole 6516. As suggested in accordance with the embodimentsabove, ring 618 may be integrally-formed into the top face 611 of cap610, or it may be attached by any number of other appropriate attachmentmethods, such as by adhesives or mechanical attachments. As illustratedin the figure, top cap 610 (and/or bottom ring 618) may have an outerdimension d₁ that is greater than the outer dimension d₃ of the filterelement 620, although it is equally acceptable to have an arrangementwherein d₁ is substantially the same as d₃, or wherein d₃ is greaterthan d₁, as discussed previously herein. As above, the top and bottomportions 610, 630 may be made of any appropriate material, such aspolymeric materials including any number of plastics, metals such assteel, or elastomeric or rubber materials, provided that the materialscan be bonded to the filter element 620, and have a flexibility suchthat the cap portion 610 can fit over the ball on the leading end of thefilter cage stem and form a seal, as described above. The embodimentshown in FIG. 11 comprises four handle portions 612 a, 612 b, 614 a, 614b, which as shown extend outwardly past the outer diameter of thefilter. Although handle portions 612 a, 612 b are illustrated as beinggenerally diametrically opposed to handles 614 a, 614 b, respectively,this is not necessary, and the plurality of handles may benon-diametricaly opposed, as desired.

The filter assemblies, and systems employing such filter assembliesdescribed herein offer several advantages over filters for vacuumappliances, especially wet/dry type vacuum cleaners, currently on themarket. In particular, due to the small amount of polymeric materialused in forming the filter assemblies, the presently disclosed filterassemblies are cheaper and more readily produced. Other advantagesinclude less time to replace or clean the filter assembly, and nocumbersome mechanical attachment mechanisms are involved, thuseliminating the possibility of lost parts otherwise necessary forattachment of the filter. Additionally, the filter assemblies describedherein may be readily retro-fit to existing vacuum appliances already inthe market and requiring these types of filters. Finally, as indicatedabove, the characteristics—both physical and mechanical—of the end capportion of the filter assemblies allows for an automatic seal of thefilter assembly onto the mounting post of the filter cage of a vacuumappliance, such seal providing a secure retaining of the filter assemblyduring normal operation, as well as during dropping, jarring or otherunexpected events.

FIGS. 12A and 12B illustrate alternative filter cage assemblies for usein association with the filter assemblies described herein, which allowfor the retrofitting of existing assemblies to the instant filterassemblies (FIG. 12A), and the conversion of filter cages as describedherein to allow for the use of standard filter assemblies and threadednut retaining means (FIG. 12B), as desired. FIG. 12 A illustrates afilter cage assembly 700 comprising a top surface 790 having a threadedstem 780 extending upwardly therefrom, and a plurality of openings 791to provide for the flow of air or other media downstream of the filterthrough the openings and into the mounting assembly for a vacuum, andthereafter subsequent exhaust, as is known in the art. These openings791 are formed by one or more longitudinally angled rib members 794 thatare formed at a zero or non-zero angle to the longitudinal axis of thefilter cage, as well as one or more circumferential ribs 792 extendingaround, and substantially circumscribing the cage 700. Optionally, theouter surface of either the longitudinally angled ribs 794 or thecircumferential ribs 792 may extend outward from the outer surface ofthe filter cage so as to allow the filter (not shown) to slide over thecage without interference from the circumferential ribs. In accordancewith this embodiment, the cage assembly may comprise a separate, formedstem 750 having sloped or otherwise shaped sides and a polygonal orspherical head, as well as interior grooves 752 formed substantiallycentral within, such as by a machining tool. Stem 750 is preferablysolid, and may be made of any appropriate material, such as plastic orother suitable polymers, or a metal, as appropriate. In use, stem 750may be simply threadably attached to stem 780 of filter cage assembly700 via the threads on stem 780, such that it mounts substantially flushwith top surface 790. In this manner, an older-style vacuum appliancemay be readily adapted for use with the filter assemblies describedherein.

FIG. 12B illustrates yet another alternative filter cage assembly 800comprising a filter cage assembly 800, similar to that described inrelation to FIG. 12A, and comprising a top surface 890 having a formed,polygonal stem 850 extending upwardly therefrom, and a plurality ofopenings 891 to provide for the flow of air or other media downstream ofthe filter through the openings and into the mounting assembly for avacuum, and thereafter subsequent exhaust, as is known in the art. Theseopenings 891 are formed by one or more longitudinally angled rib members892 that are formed at a zero or non-zero angle to the longitudinal axisof the filter cage, as well as one or more circumferential ribs 894extending around, and substantially circumscribing the cage 800.Optionally, the outer surface of either the longitudinally angled ribs892 or the circumferential ribs 894 may extend outward from the outersurface of the filter cage so as to allow the filter (not shown) toslide over the cage without interference from the circumferential ribs.The assembly illustrated in FIG. 12B further comprises adapter 860suitable for converting a filter cage assembly from those such asdescribed herein to a standard filter cage assembly having a threadedstem. Adapter 860 is preferably a solid piece of formed, extruded, ormachined material (including but not limited to plastic, polymericmaterials, elastomers, metal, and the like) having two or more spacedapart sides 863, 865, a top face 862, and a bottom face 864 which in usemakes contact with top surface 890 of filter cage assembly 800. The topface 862 of adapter 860 comprises a threaded stem 866. Adapter 860further comprises a shaped, interior portion 870, formed in anappropriate shape such that in use, adapter 860 may be simply pusheddownward in the direction of the arrow onto and over shaped stem 850,such that the bottom face of the adapter 864 makes contact with top face890 of the cage.

FIGS. 12C-12E illustrate further, alternative filter cage assemblies 880and 880′ in accordance with aspects of the present disclosure andsuitable for use in association with the filter assemblies of thepresent disclosure. FIG. 12C illustrates a partial perspective view offilter cage assembly 880 comprising a generally planar surface 882 ofthe bottom end of the cage assembly 880, having a formed projection 884,such as a mounting post or stem, extending upwardly therefrom.Projection 884 may be shaped as shown to include a neck region 883 and ahead portion 887, such that neck region 883 is intermediate between thesurface 882 of the cage assembly, and the head portion 887. As furthershown in FIG. 12C, projection 884 may further comprise one or moreoutwardly-projecting ribs 885 formed into and circumscribing neck region883, such ribs acting to further retain filter assemblies of the presentdisclosure when they are inserted into place over cage assembly 880 asit is associated with a vacuum appliance, such as described hereinabove. Cage assembly 880 also comprises one or more longitudinallyangled rib members 886 that are formed at a zero or non-zero angle tothe longitudinal axis of the filter cage, as well as one or morecircumferential ribs 888 extending around, and substantiallycircumscribing the cage 800. These ribs in combination define aplurality of openings 891 as shown in the figure, which as describedabove provide for the flow of air or other media downstream of thefilter through the openings and into the mounting assembly for a vacuum,and thereafter subsequently exhaust the air. Optionally, the outersurface of either the longitudinally angled ribs 894 or thecircumferential ribs 888 may extend outward from the outer surface ofthe filter cage so as to allow the filter (not shown) to slide over thecage without frictional interference from the circumferential ribs.

FIG. 12D illustrates a perspective view of a further, alternative filtercage assembly 880′ in accordance with aspects of the present disclosureand suitable for use in association with the filter assemblies of thepresent disclosure. Similar to the cage assembly 880 of FIG. 12C,assembly 880′ includes a generally planar bottom surface 882, as well aslongitudinal and circumferential rib members 886 and 888 (respectively)which in combination define openings 891 as discussed previously. Cageassembly 880′ also comprises a formed projection 884, such as a mountingpost or stem, extending outwardly away from surface 882. Projection 884may be shaped as shown to include a shoulder region 881 elevating theprojection from surface 882, neck region 883 and a head portion 887,such that neck region 883 is positioned between the shoulder region 881of the projection 884, and the head portion 887. As also illustratedtherein, neck region 883 may further comprise one or more rib members885 circumscribing the neck region 883, and which may be useful inretaining filter assemblies in accordance with the present disclosure inplace over cage 880′. The head portion 887 as illustrated in the figuremay be semi-hemispherical in shape as shown, although any shape may beused as appropriate, and may also include one or more formed indents 889which may act as grips for the user during installation and removal of afilter assembly as described herein onto and over the cage 880′. FIG.12E is a cross-sectional view of the filter cage assembly 880′ of FIG.12D, taken along line 12-12, and illustrating more clearly the spatialrelationship of the head, neck, should and rib portions of projection884 as it extends outwardly away from the surface 882 (typically thebottom surface) of the cage.

In further aspects of the present disclosure, the center sealingassemblies described herein, comprising an annular center holecircumscribed by a collar which adds strength and provides for anelastomeric retention of the filter assembly over a filter cage of avacuum appliance, may be provided in a separate element apart from thefilter itself. In example, a filter assembly may comprise a firstportion and a second portion, wherein the first portion comprises ashaped filter, optionally further comprising an end ring for sealinglyengaging with the inner face of a vacuum motor mount. In accordance withthis aspect, the second portion may comprise a separate cap portionhaving a centrally located annular hole extending therethrough and aretaining ring or collar circumscribing the annular hole. During use,the first portion comprising the filter would be placed over the filtercage of the vacuum assembly, whereafter the separate, second portionwould then be placed over the top of the first filter portion, such thatthe mounting stem or post on the bottom face of the filter cage extendsthrough the annular hole in the cap portion in a manner as describedpreviously herein. That is, the annular hole preferably has a diameterthat is smaller than the diameter at least a portion of the mountingpost, for example a diameter of the leading end of the mounting stem orpost on the filter cage, (which may or not be hour-glass shaped), suchthat as the second portion is pushed over at least a portion of themounting stem, the annular hole expands to go over the stem, and thencontracts back to its original diameter as the second portion sealsagainst the bottom face of the filter cage, thereby sealably engagingthe first filter portion against the lower part of the vacuum head. Inaccordance with this aspect, similar to aspects described above, theretaining ring or collar on the second portion can aid in holding thesecond portion in place against the first filter portion by constrictingagainst the mounting stem.

Several of the above-described embodiments of the present disclosure areillustrated generally in FIGS. 13A-13E. FIGS. 13A, 13B and 13Cillustrate top views of a cap section 900, 900′, and 900″, respectively,each having a differently shaped hole, orifice, or opening (902, 904,906) within and extending through, the cap sections. For example, inFIG. 13A, opening 902 is generally keyhole-shaped, and optionallyoff-center, such that in use the stem of the filter cage assembly maycome up and through the opening 902, after which the entire filterassembly is shifted in such a manner as to lockably engage the stem ofthe filter cage and the filter assembly, thus making the use of aretaining ring as described herein optional or unnecessary. In FIG. 13A,opening 904 is a plurality (2 or more) of slits in the cap section 900′,which allow for the stem of the filter cage assembly to extend up andthrough the top cap section of the filter assembly, while still allowingfor the formation of a suitable seal of the filter assembly against thefilter cage. Similarly, in FIG. 13C, cap section 900″ comprises a singleslit 906 extending through a portion of the cap 900″, and which allowsthe stem of a filter cage to extend up and through the cap section 900″of a filter assembly of the present disclosure. Advantageously, theembodiment illustrated in FIG. 13C allows for the use of filters such asdescribed herein with a range of different vacuum appliances havingdifferently-placed and shaped filter cages. While integrally-formedhandles and support members, such as described above, are not includedin these figures for purposes of clarity, their optional inclusion withthese embodiments is contemplated as described herein.

In FIG. 13D, a partial perspective view of an alternative embodiment ofa filter assembly in accordance with the present disclosure isillustrated, which comprises a cap section 910, an end ring 930 (notshown), and, a generally cylindrically-shaped, pleated filter 920intermediate between cap 910 and end ring 130 and extending in a closed,circumferential path and which includes a closed, interior path. The cap910 may further, optionally comprise a formed hole 952 in the center ofthe cap, centrally-formed opening 952 extending from the top surface 950of cap 910 through the cap to the closed, interior airflow path formedby filter 120. While opening 952 is illustrated to be substantiallyannular herein, it is contemplated that it may of any number of shapesand styles, as described herein. As also illustrated in FIG. 13D, thefilter assembly may comprise a separate retaining member 960 for usewith retaining the filter assembly in association with a filter cage ofa vacuum assembly. In general, it is envisioned that in use, the filterelement 920 would be placed over the filter cage of a vacuum appliance(not shown), cap 910 would then be placed over the top of the filter,such that the stem of the filter cage extends up and through opening952, after which retaining member 960 would be slid down and over thestem, and hold the assembly in place. In accordance with the presentdisclosure, it is envisioned that the cap 910 may also optionallycomprise a plurality of integrally-formed support struts (illustrated inhashed lines), to add structural integrity to the cap section 910, aswell as one or more optional handles (not shown).

FIG. 13E illustrates a further embodiment of the present disclosure,similar to that shown in FIG. 13D, but wherein the retaining member 988is connected to the top face 980 of cap 970 by a flexible member 987,which may be made of the same, or different, material as that which thecap 970 itself is made from. In use, once the filter assembly has beenplaced over the filter cage of the vacuum appliance, such that the stemof the filter cage extends upward through opening 986, the user may thenextend retaining member 988, via flexible member 987, up and over thestem, so as to hold the entire filter assembly in place. Advantageously,this embodiment allows for the use of an optional filter retainingmember 988 which is directly connected to the top face 980 of the filtercap 970, and which can be used or not used, depending upon the specificvacuum appliance with which the assembly is being associated. Similar tothe caps described herein above, cap 970 may optionally comprise one ormore integrally-formed support struts (illustrated in hashed lines), inorder to add structural strength and integrity to the cap section 970,as well as one or more optional handles 982, 984, as appropriate.

FIGS. 14A and 14B illustrate a further embodiment of the presentdisclosure, wherein the snap-on filter assembly 1000 is shown without anopening or orifice, but rather with a stem-cap 1040 integrally formedwith the filter cap itself. Filter assembly 1000 comprises anintegrally-formed integrated cap section 1010, spaced-apart, annular endring 1030, and a generally cylindrically-shaped, pleated filter 1020intermediate between cap 1010 and end ring 1030, the filter element 1020extending in a generally closed, circumferential path and which includesa closed, interior path (not shown). As illustrated in the Figure, theintegrated cap 1010 may further, optionally comprise one or more (twoare shown) integrally-formed handles 1012, 1014 as shown and describedpreviously, a formed edge or rim 1017 circumscribing the exterior of thecap 1010, and an opening 1041 (not shown), such as a formed or moldedhole or other appropriate opening, formed in the cap, wherein theopening 1041 is covered by stem cover means 1040 which extends upwardlyfrom the top surface 1011 of cap 1010. As can be seen in FIG. 14B,described in more detail below, opening 1041 extends from the topsurface 1011 of cap 1010 through the cap to the closed, interior airflowpath 1050 formed by filter element 1020. As further illustrated in FIG.14A, the cap 1010 may also optionally comprise a plurality ofintegrally-formed support struts 1015, to add structural integrity tothe cap section 1010. As illustrated in the Figure, struts 1015 mayextend radially outward from the stem cover means 1040 towards, andoptionally integrate with, rim 1017 of the cap. While twohandle-portions 1012 and 1014 are illustrated, it will be recognizedthat the filter assemblies described herein may have no handles, asingle handle, or more than two handles, which may be oriented in avariety of manners, such as perpendicular to the top face of the capportion or in a plane substantially in alignment with the top surface ofcap 1010, without limitation.

As illustrated more clearly in FIG. 14B, which is a cross-sectional viewof the filter assembly 1000 of FIG. 14A, taken along line 14-14, thestem cap or stem cover means 1040 comprises an outer portion 1044, aninterior opening 1041 opening into the central region of the filterassembly 1000 and opposite the top face of cap 1011, and a shaped innerregion 1042 which may optionally further comprise an inner grippingportion or gripping means 1046. The stem cover means 1040 is arranged tobe placed over the stem or stem head (not shown) of the filter cage whenthe filter assembly 1000 is engaged with a vacuum appliance as describedabove. In accordance with one aspect of this embodiment, the stem covermeans 1040 may be retained in position by means of the shaped innerregion 1042, alone or in combination with one or more optional grippingmeans 1046 which can act to grip the filter cage stem or stem head andretain the filter assembly 1000 in place, engaged with the vacuumappliance. In accordance with certain aspects of this embodiment, thecover means 1040 may be substantially hollow, having a shaped innerregion 1042 whose shape corresponds to the filter cage stem with whichit will interact and engage. While the cover means 1040 is illustratedto be substantially cylindrical in shape, it may have a domed orotherwise shaped outer section 1044, which is opposite the opening 1041in the cover means. The optional gripping means 1046 may comprise one ormore resilient arms or equivalent gripping means so as to more tightlyengage the stem or stem head of a filter cage, particularly when thestem is not shaped, but rather is of standard, cylindrical (threaded ornot) design.

In an exemplary typical method of use, the filter assembly 1100 issimply pushed down onto and over an exposed filter cage assembly portionof a vacuum appliance, such as the type illustrated generally in FIG. 6herein, wherein interior air flowpath 1050 defined at least in part byfilter 1020 circumscribes the exterior of the filter cage assembly. Theassembly 1100 is pushed down such that stem cover 1040 is simply pushedonto the exposed and downwardly-extending filter cage stem head. Theshaped inner region 1042 of the stem cover 1040 is just smaller than theouter width of the cage stem head, so that when pushed onto a vacuumappliance cage stem, the inner region 1042 deforms slightly and gripsthe cage stem. Alternatively, and equally acceptable, in the event thatone or more gripping means are included within stem cover 1040, theinner region 1042 will be slightly larger than the outer width of thecage stem head, so that when pushed onto a vacuum appliance cage stem,the gripping means 1046 deform slightly and thereby grip the cage stem.Tension between the shaped inner region 1042 and the cage stem, orbetween the gripping means 1046 and the cage stem will work to retainthe filter assembly 1000 in place and engaged with a vacuum appliance,even when vacuum is not being applied.

FIG. 15 illustrates a perspective view of a further embodiment of thepresent disclosure, the design of filter assembly 1100. Filter assembly1100 is a design variant of the filter assembly 100 described herein,and which comprises an integrally-formed integrated cap section 1110,spaced-apart, annular end ring 1130, and a generallycylindrically-shaped, pleated filter element 1120 intermediate betweencap 1110 and end ring 1130, the filter 1120 extending in a generallyclosed, circumferential path and which includes a closed, interior path(not shown). As illustrated in the Figure, the integrated cap 1110 mayfurther, optionally comprise one or more (two are shown)integrally-formed handles 1112, 1114 as shown, a formed edge or rim1117, and an opening 1118, such as a formed or molded hole, slit, orother appropriate opening, formed either in the center of the cap 1110,or formed off-center of the central, vertical axis of the filter, asappropriate. Opening 1118 extends from the top surface 1111 of cap 1110through the cap to the closed, interior airflow path formed by filter1120. The cap 1110 may also optionally comprise a plurality ofintegrally-formed support struts 1115, to add structural integrity tothe cap section 1110. As illustrated in the Figure, struts 1115 mayextend radially outward from the opening 1118 towards, and optionallyintegrate with, rim 1117 of the cap. In a non-limiting manner, and asshown in the figure, the handle portions 1112 and 1114 may besubstantially diametrically opposed in orientation, and can extendpartially over the top and edges of the pleated filter element 1120, soas to allow for providing the user with a gripping surface to aid infilter removal from the filter cage of a vacuum appliance when changingfilters. While two handle-portions 1112 and 1114 are illustrated, itwill be recognized that the filter assemblies described herein may haveno handles, a single handle, or more than two handles, which may beoriented in a variety of manners, such as perpendicular to the top faceof the cap portion or in a plane substantially in alignment with the topsurface of cap 1110, without limitation. As also illustrated in FIG. 15,the opening 1118 in cap 1110 can be optionally circumscribed by anintegrally- or non-integrally formed annular retaining ring 1116 havinga general taurus-like (donut) shape (or other shape, as desired orappropriate) of such a size, shape and internal diameter that the ballor lead-end flange on the leading end of a mounting shaft on a vacuum'sfilter cage can be forced up and through the opening 1118, in a manneras discussed herein above, so as to retain a filter assembly of thepresent disclosure on the filter cage and seated against the base of thevacuum appliance. If retaining ring 1116 is integral, it will be formedinto cap 1110 as part of the manufacturing process. In the event thatring 1116 is non-integral and is a separate element of the filterassembly, it may be attached to the top surface 1111 through any numberof appropriate chemical (e.g., glue) or mechanical methods, withoutlimitation.

In FIG. 16, a perspective view of the design of a filter assembly 1200is illustrated, in a manner similar to that presented in FIG. 15. Asshown therein, the filter assembly 1200 comprises an integrally-formedan integrated cap section 1210, an end ring 1230, and, a generallycylindrically-shaped, pleated filter element 1220 intermediate betweencap 1210 and end ring 1230 and extending in a closed, circumferentialpath and which includes a closed, interior path (not shown), similar tothe design of filter assembly 100 described above. As illustrated in theFigure, the integrated cap 1210 may further, optionally comprise one ormore (two are shown) integrally-formed handles 1212, 1214 as shown, aformed intermediate rim 1217, an opening 1218, such as a formed ormolded hole, slit, or other appropriate opening, formed either in thecenter of the cap 1210, or formed off-center of the central, verticalaxis of the filter, as appropriate. Opening 1218 extends from the topsurface 1211 of cap 1210 through the cap to the closed, interior airflowpath formed by filter element 1220. The cap 1210 may also optionallycomprise a plurality of integrally-formed support struts 1215, to addstructural integrity to the cap section 110. As illustrated in theFigure, struts 1215 may extend radially outward from the opening 1218towards, and optionally integrate with, intermediate rim 1217 of thecap. As also shown in FIG. 16, cap 1210 of filter 1200 may furthercomprise an outer edge region 1219 that substantially circumscribes therim 1217, and extends outwardly to a distance such that its outer edge1222 is substantially in the same plane as, and does not extend past,the outer edge (diameter d.sub.3) of the filter element 1220. In anon-limiting manner, and as shown in the figure, the handle portions1212 and 1214 may be substantially diametrically opposed in orientation,and can extend partially over the top and edges of the pleated filterelement 1220, so as to allow for providing the user with a grippingsurface to aid in filter removal from the filter cage of a vacuumappliance when changing filters. While two handle-portions 1212 and 1214are illustrated, it will be recognized that the filter assembliesdescribed herein may have no handles, a single handle, or more than twohandles, which may be oriented in a variety of manners, such asperpendicular to the top face of the cap portion or in a planesubstantially in alignment with the top surface of cap 1110, withoutlimitation. As also illustrated in FIG. 16, the opening 1218 in cap 1210can be optionally circumscribed by an integrally- or non-integrallyformed annular retaining ring 1216 having a general shape of such asize, shape and internal diameter that the ball or lead-end flange onthe leading end of a mounting shaft on a vacuum appliance's filter cagecan be forced up and through the opening 1218, in a manner as discussedherein above, so as to retain a filter assembly 1200 of the presentdisclosure on the filter cage (not shown) and seated against the base ofthe vacuum appliance. If retaining ring 1216 is integral, it willpreferably be formed into cap 1210 as part of the manufacturing process.In the event that ring 1216 is non-integral and is a separate element ofthe filter assembly, it may be attached to the top surface 1211 throughany number of appropriate chemical (e.g., glue) or mechanical methods ormechanical means (such as by a flexible hinge portion of elastomericmaterial), without limitation, as described above.

A common issue surrounding the use of wet/dry vacuums is that theirfilters are not suitable for use with wet materials. When the typicalwet/dry vacuum filters having paper or similar types of filter elementsare exposed to water or even wet materials (e.g., wet leaves), the watertends to wet-out the paper filters and quickly destroys them under theharsh conditions of vacuuming. Consequently, such filters must either beremoved prior to use of the wet/dry vacuum appliance with wet debris, orreplaced frequently due to their rapid rate of clogging, making themlargely unsuitable for use with wet debris pickup. Wet vacuum cleaningis further complicated by a number of other factors. First, while wetdirt and debris are inclined to stay in the tank and not becomeentrained into the exhaust from the vacuum cleaner, the cleaning ofmixed wet and dry materials without a filter in place can lead to dustspewing from the exhaust. Further, even in instances where only liquidis being collected, the liquid tends to become aerosolized and exhaustedfrom the vacuum. In addition, most wet/dry vacs include cut-off valvesto prevent liquid from being drawn through the suction unit when thetank becomes filled with a liquid. However, these valves tend to engageonly at the last minute, usually resulting in at least some spillage ordispersion of liquid from the vacuum cleaner. The filter assembly 1300shown in FIG. 17 and the related figures addresses these issues.

FIG. 17 illustrates a perspective view of an exemplary filter assemblyin accordance with a further aspect of the present invention related towet debris pickup. FIG. 18 illustrates a side view of the filterassembly of FIG. 17. FIG. 19 illustrates a bottom perspective view ofthe filter assembly of FIG. 17. FIG. 20 illustrates a top view of thefilter assembly of FIG. 17. FIG. 21 illustrates a cross-sectional viewof the exemplary filter assembly of FIG. 17. These figures will bediscussed in combination with each other.

In FIG. 17, a perspective view of filter assembly 1300 for wet debrispickup (“wet use”) is illustrated, which comprises an integrally-formedintegrated end plate section 1310, an end seal ring 1330 (not shown),and, a generally cylindrically-shaped, filter element 1320 intermediatebetween cap 1310 and end seal ring 1330 and extending in a closed,circumferential path which includes and forms a closed, interior region.The integrated end plate 1310, equivalently referred to herein as a“cap”, may further, optionally comprise one, two or more (e.g., three,four, five, etc.) integrally-formed handle portions 1312, 1314 (two areshown), and a formed hole or opening 1318 in or substantially near thecenter of the end-plate, the centrally-formed opening 1318 extendingfrom the top surface 1311 of end plate 1310 through to the closed,interior airflow path formed by filter element 1320. The end plate 1310may also optionally comprise a plurality of support struts 1315 to addstructural integrity to the end plate itself, such support struts beingoptionally integrally-formed with the top surface 1310 or non-integrallyformed. As shown in the figure, the handle portions 1312 and 1314 may besubstantially diametrically opposed in orientation, and can extendpartially over the top and edges of the filter element 1320, so as toallow for providing the user with a gripping surface to aid in filterremoval from the filter cage of a vacuum appliance when changingfilters. While two handle-portions 1312 and 1314 are illustrated, itwill be recognized that the filter assemblies described herein may haveno handles, a single handle, or more than two handles (e.g., three orfour handles), which may be oriented in a variety of manners, such asperpendicular to the top face of the cap portion, without limitation. Asalso illustrated in FIG. 17, the opening 1318 in cap 1310 can becircumscribed by an integrally- or non-integrally formed annularretaining means, such as retaining ring 1316 having a generaltaurus-like (donut) shape of such a size, shape and internal diameterthat the ball or end flange on the leading end of mounting shaft on avacuum's filter cage can be forced up and through the opening 1318 ashas been discussed previously herein (see, for example, the discussionsurrounding the exemplary filter assembly of FIG. 2), so as to retain afilter assembly of the present disclosure on the filter cage and seatedagainst the base of the vacuum appliance. If retaining ring 1316 isintegral, it will be formed into end plate 1310 as part of themanufacturing process. In the event that ring 1316 is non-integral andis a separate element of the filter assembly, it may be attached to thetop surface 1311 through any number of appropriate chemical (e.g., glue)or mechanical methods, without limitation.

FIG. 18 illustrates a side view of the filter assembly 1300 of FIG. 17,showing in particular the dimensional relationships between theintegrated end plate 1310, the filter element 1320, and the end sealring 1330. As shown therein, in one non-limiting, exemplary aspect ofthe disclosure, the integrated top mounting end plate 1310 has an outerdiameter d₁ which is equal in all orientations, due the substantiallycircular shape of end plate 1310. Filter element 1320, which isintegrally attached to the bottom face of end plate 1310, has an outerdiameter d₃. In accordance with this non-limiting, exemplary aspect ofthe present disclosure, the outer diameter d₃ of filter element 1320 canbe greater than the outer diameter d₁ of end plate 1310. As illustrated,only the formed handles 1312, 1314 extend outwardly in such a manner asto extend over the outer edge of filter element 1320, such that thediameter d₂ between the outer edges of the handles 1312, 1314 is greaterthan the outer diameter d₃ of filter element 1320.

FIG. 19 illustrates a perspective bottom view of the exemplary wetfilter 1300, showing the end seal ring 1330 and an embodiment whereinthe filter element 1320 on the exterior of the filter assembly 1300 canalso include at least one interior, secondary filter element 1352, thesecondary filter element being interior to the primary filter element1320. Similar to filter element 1320, secondary filter element 1352circumscribes the interior region of the filter assembly, and is alsointermediate between cap 1310 and end seal ring 1330, extending in aclosed, circumferential path which includes and forms the closed,interior region.

FIG. 20 illustrates an exemplary top view of the filter assembly 1300 ofFIG. 17, showing an embodiment wherein the outer edge of filter element1320 extends beyond the outer edge 1360 of end plate 1310 (e.g., d₃ isgreater than d₁, with reference to FIG. 18). FIG. 21 illustrates aperspective, cross-sectional view of the exemplary filter 1300 of thepresent disclosure generally illustrated in FIG. 17, taken along line21-21, and showing the filter seals, primary filter element 1320,secondary filter element 1352 of the filter element assembly 1350, andend plate 1310. As shown in the Figure, secondary filter element 1352,which will be described below in more detail below, is attached to theend plate 1310 and the end sealing cap 1330 and is arranged insideprimary filter element 1320, such that it circumscribes the interiorregion of filter 1300. FIG. 22 illustrates an alternative view of thearrangement of the filter elements with respect to each other, such thatfilter element 1320 is on the exterior of the filter assembly 1300, andthe secondary filter element, screen 1352, is on the interior of thefilter assembly.

FIGS. 23 and 24 illustrate a further embodiment of the presentdisclosure, wherein the filter element assembly 1350 is comprised of theprimary filter element 1320, an intermediate, secondary filter element1352, such as a filter screen element, and an inner-most, interiortertiary filter element 1354, which is also preferably a filter screenelement. As illustrated generally in FIG. 23, filter element 1352 has ascreen mesh size that is larger than that of the inner-most filterelement 1354. The secondary filter element 1352 may also have a screenmesh size less than or substantially equivalent to the pore size of theprimary filter element 1320, which is in the preferred embodiments anopen-cell polyurethane foam filter material.

The primary filter element 1320 suitable for use with the wet-filterassembly 1300 illustrated herein is preferably a foam material, and morepreferably is an open cell polyurethane (PU) foam material, such as apolyester polyurethane (PU) foam material. Such a material for filterelement 1320 is capable of repeated exposure to water and aqueous debriswithout degradation, and allows for air flow through the filter elementduring wet debris pickup. The thickness of the open cell PU foam primaryfilter element 1320 can vary from about 0.1 in. to about 2.0″, morepreferably from about 0.25 in. to about 1.5 in., including about 0.5in., about 0.75 in., about 1.0 in., and about 1.25 in., inclusive, aswell as ranges between these range values, such as from about 0.5 in. toabout 0.75 in. These PU foam materials may be obtained from any suitableopen-cell polyurethane foam-forming reaction, such as between a polyoland an isocyanate, using any suitable type of blowing agent (e.g.,water). As used herein, the terms “open cell” and “open cell foam” meanfoam possessing an interconnection or opening between adjacent cells,the open cell content being expressed as a percent when measuredaccording to ASTM D-2856-A or an equivalent test method. Preferably, inaccordance with aspects of this embodiment of the invention, the PU foamwill have an open cell content according to ASTM D 2856-A ranging from20-80% (±5%), inclusive. Alternatively, or in addition to the open foamcontent characteristics, the PU foam material useful as the primaryfilter element 1320 is a PU foam having a cell structure with about 10pores per inch (ppi) to about 60 pores per inch (ppi), inclusive (±5ppi), including from about 15 ppi to about 50 ppi (±5 ppi), and fromabout 20 ppi to about 40 ppi (inclusive), ±5 ppi, as determined usingASTM D 3574 or an equivalent test method.

The secondary filter screen element 1352, and the tertiary filter screenelement 1354, when used, are selected such that the screen elements 1352and 1354 have mesh sizes that are not equivalent (e.g., the secondaryfilter element has a screen mesh size greater than that of the tertiaryfilter element, and vice versa), and are capable of being formed intomesh cages. The filter screen elements may be made of any appropriatematerial, including polymers, metals, and metal alloys. In accordancewith select aspects of the disclosure, the mesh can be formed fromstainless steel wire, though other corrosion resistant metals can beemployed for the mesh (e.g. such as copper, galvanized steel wire, etc).In accordance with select aspects of the invention, the filter screenmaterial can be a woven metal wire mesh (such as steel) of select meshsize that is coated with one or more polymeric materials, or hot dipgalvanized.

The secondary and tertiary filter elements, filter screens 1352 and1354, when used in combination with the primary filter element 1320, aresandwiched together prior to being formed into filter assembly 1300intermediate between end plate 1310 and end ring 1330. As illustrated inFIG. 24, it is preferable that secondary filter element (filter screen1352) is sandwiched between the primary filter element 1320 and tertiaryfilter element (filter screen 1354). As is also illustrated in thisfigure, the mesh size of screen 1352 is preferably greater than that ofscreen 1354. Alternatively, while not shown, the mesh size of screen1352 can be less than that of screen 1354. The mesh size of thesecondary and tertiary filter elements (filter screens 1352 and 1354)can be described in terms of the warp and weft of the screen, thescreens being generally comprised of a plurality of warp elements and aplurality of weft elements interwoven with one another in a repeatingweave pattern. In accordance with select aspects of the invention, theweft can range from about 1 mm to about 15 mm, more preferably fromabout 2 mm to about 10 mm, and the warp can range from about 2 mm toabout 20 mm, more preferably from about 4 mm to about 15 mm, inclusive.In one non-limiting example, the screen can have a mesh defined by aweave with a weft of about 5 mm and a warp of about 7 mm. In anothernon-limiting example, the screen can be defined by a mesh with a weavehaving a weft and/or weave of about 4.7 mm. Alternatively andequivalents, the mesh size of the screens 1352, 1354 can be described interms of ASTM mesh size, such as from ASTM mesh size 3 to ASTM mesh size80, including about ASTM 3.5, ASTM 4, ASTM 5, ASTM 6, ASTM 7, ASTM 8,ASTM 9, ASTM 10, ASTM 12, ASTM 14, ASTM 16, ASTM 18, ASTM 20, ASTM 25,ASTM 30, ASTM 35, ASTM 40, ASTM 45, ASTM 50, ASTM 60, and ASTM 70.

FIGS. 24 and 25 illustrate an exemplary embodiment of the disclosurewherein filter assembly 1300 has a top end plate 1310′ with an outer rim1360 with a diameter that is substantially coincident with the outeredge of the filter element 1320. Similarly, as shown in the bottom viewof FIG. 25, the end seal ring 1330 can also have an outer edge 1331 witha diameter that is substantially coincident with the outer edge of thefilter element 1320.

Other and further embodiments utilizing one or more aspects of theinventions described above can be devised without departing from thespirit of Applicant's invention. For example, combinations of featuresshown may be combined, and materials other than those recited may beused with similar results. In such an example, any of the filterassemblies described herein may include a single handle element thatextends radially outward from the center hole in the top end plate,extending beyond the outer facial edge of the filter element. Further,the various methods and embodiments of the methods of manufacture andassembly of the system, as well as location specifications, can beincluded in combination with each other to produce variations of thedisclosed methods and embodiments. Discussion of singular elements caninclude plural elements and vice-versa.

The order of steps can occur in a variety of sequences unless otherwisespecifically limited. The various steps described herein can be combinedwith other steps, interlineated with the stated steps, and/or split intomultiple steps. Similarly, elements have been described functionally andcan be embodied as separate components or can be combined intocomponents having multiple functions.

The inventions have been described in the context of preferred and otherembodiments and not every embodiment of the invention has beendescribed. Obvious modifications and alterations to the describedembodiments are available to those of ordinary skill in the art. Thedisclosed and undisclosed embodiments are not intended to limit orrestrict the scope or applicability of the invention conceived of by theApplicants, but rather, in conformity with the patent laws, Applicantsintend to fully protect all such modifications and improvements thatcome within the scope or range of equivalent of the following claims.

1. A filter for use with a wet/dry vacuum appliance, the filtercomprising: an end plate having an opening extending therethrough; aplurality of support struts on the top surface of the end plate; anannular end ring oriented parallel to the end plate; and a foam filterelement positioned between the end plate and the end ring and extendingin a circumferential path that forms a closed, interior region andcircumscribes a central longitudinal axis of the filter, the filterelement being integrally formed with the end plate and the annular ringto form a single filter assembly, wherein the opening in the cap issubstantially centrally located about the central longitudinal axis ofthe filter and is circumscribed by an integral retaining ring, andwherein the filter element is made of an open-cell polyurethane foam. 2.The filter of claim 1, wherein the open-cell polyurethane foam has acell structure with about 10 pores per inch (ppi) to about 60 ppi. 3.(canceled)
 4. The filter of claim 1, further comprising a firstcylindrical, concentric mesh screen filter element oriented on theinterior face of the foam filter element and extending between the endplate and the end ring, the mesh screen filter element having aplurality of air-flow openings in the mesh.
 5. The filter of claim 4,further comprising a second cylindrical, concentric mesh screen filterelement, the second filter element having larger through air-flowopenings than the openings on the first screen filter element.
 6. Thefilter of claim 5, wherein the second mesh screen filter element islocated between the first screen filter element and the foam filtersleeve.
 7. The filter of claim 4, wherein the first screen filterelement has through air-flow openings in a mesh size ranging from ASTM 3to about ASTM
 80. 8. The filter of claim 5, wherein the second screenfilter element has through air-flow openings in a mesh size ranging fromabout ASTM 3 to about ASTM
 80. 9. The filter of claim 1, wherein the capfurther comprises two or more integrally formed handles.
 10. The filterof claim 1, wherein the end plate has a diameter that is substantiallycoincident with the outside diameter of the foam filter element.
 11. Afilter for use with a wet/dry vacuum appliance having a collection drum,a lid attachable to the top of the collection drum and housing a motor,and a filter cage attached to the bottom face of the lid and extendingdownwardly toward the interior of the drum, the filter comprising: a capportion having a substantially centrally located opening extendingthrough the center of the cap; an annular end ring; a foam filterelement positioned between the cap and the end ring and extending in acircumferential path that forms a closed, interior region sized to fitover the outer periphery of the filter cage, the filter element beingintegrally formed with the cap portion and the annular ring to form asingle filter assembly; and a first concentric mesh screen filterelement oriented on the interior face of the foam filter sleeve andhaving through air-flow openings in the mesh, wherein the opening in thecap portion is circumscribed by a retaining ring, and wherein the endring is comprised of a flexible material bonded to the filter and shapedto engage the bottom surface of the lid.
 12. The filter of claim 11,wherein the foam filter element is comprised of perforated resin, opencell foam, or a mixture thereof.
 13. The filter of claim 12, wherein thefoam filter element is an open cell foam having a cell structure withabout 10 pores per inch (ppi) to about 60 ppi.
 14. The filter of claim11, further comprising one or more integrally-formed support struts onthe top surface of the cap portion.
 15. The filter of claim 11, whereinthe cap further comprises two or more integrally formed handles.
 16. Thefilter of claim 15, wherein the two or more integrally formed handlesare located in the same plane as the top surface of the cap.
 17. Thefilter of claim 15, wherein two of the integrally formed handles arediametrically opposed.
 18. The filter of claim 15, wherein two of theintegrally formed handles are non-diametrically opposed.
 19. The filterof claim 1, further comprising a second cylindrical, concentric meshscreen filter element, the second filter element having larger throughair-flow openings than the openings on the first screen filter element.20. The filter of claim 19, wherein the second screen filter element islocated between the first screen filter element and the foam filtersleeve.
 21. The filter of claim 1, wherein the first screen element hasthrough air-flow openings in a mesh size ranging from about ASTM 3 toabout ASTM
 80. 22. The filter of claim 19, wherein the second screenelement has through air-flow openings in a mesh size ranging from aboutASTM 3 to about ASTM
 80. 23. The filter of claim 11, wherein the filterfurther comprise one or more biostatic and/or biocidal agents.
 24. Thefilter of claim 11, wherein the flexible material is a metal, apolymeric material, or an elastomeric material.
 25. The filter of claim24, wherein the flexible material is an elastomeric material comprisinga two-part polyurethane foam material exhibiting an elongation asdetermined by ASTM D-1564 of from about 90% to about 200%.
 26. Aone-piece filter for use with a wet/dry vacuum appliance having acollection drum, a lid attachable to the top of the collection drum andhousing a motor, and a filter cage attached to the bottom face of thelid and extending downwardly toward the interior of the drum, the filtercomprising: a cap portion having a substantially centrally locatedopening extending through the center of the cap, the cap including twoor more integrally formed handles, at least two of the handles beingspaced approximately 180 degrees apart; an annular end ring shaped toengage the bottom surface of the lid; and a foam filter element made ofan open-cell polyurethane foam positioned between the cap and the endring and extending in a circumferential path that forms a closed,interior region sized to fit over the outer periphery of the filtercage, the foam filter element being integrally formed with the capportion and the annular ring to form a single filter assembly; a firstconcentric mesh screen filter element oriented near the interior face ofthe foam filter sleeve and having through air-flow openings in the mesh;and a second, concentric mesh screen filter element oriented near theinterior face of the foam filter sleeve and having through air-flowopenings in the mesh, the air-flow openings being larger than theopenings in the first mesh screen filter element, wherein the centrallylocated annular hole is circumscribed by a retaining structure, andwherein the cap and the end ring are comprised of a flexible materialbonded to the filter.
 27. The filter of claim 26, wherein the cap, theend ring, or both the cap and the end ring have a diameter that issubstantially coincident with the outside diameter of the foam filterelement.
 28. The filter of claim 26, wherein when the cap is inassociation with the wet/dry vacuum appliance, the cap seals on a planebelow the top surface of the filter.
 29. The filter of claim 26, whereinthe first screen filter element has a mesh size ranging from about ASTM3 to about ASTM
 80. 30. The filter of claim 26, wherein the cap furthercomprises two or more integrally formed handles.